Sam Rapira is up for his biggest test of his professional career in Hamilton on Saturday night.

The New Plymouth light heavyweight boxer returns to the ring on the undercard of the heavyweight showdown between David Tua and Alexander Ustinov at the Claudelands Arena.

Event promoters Ducco yesterday confirmed Rapira would trade blows with Fijian No 1 light heavyweight Isaia Maku junior, who is undefeated winning six of his nine bouts including five by knockout. Two other fights he had were drawn and one was a no-contest.

"I'm ready for this. I'm mentally prepared and physically prepared," Rapira said yesterday from Auckland where he is on his final leg of preparation for what will be his fourth pro fight having won his previous three.

"This is going to be my biggest test since I turned pro, which I'm really excited about. I want a really tough fight."

Rapira is not intimidated by Maku's impressive form or that he is No 1 in his country.

"I've been up against those sorts of odds in the amateur ranks and that experience has helped me prepare for the pros because I've fought people that have been the best in their country and won."

But power is power and with five KOs to Maku's name, Rapira will need his defence to be true.

The promotional material describes Maku as brutal.

"He fights wild and he fights hard," according to the blurb.

Rapira will be the first opponent the Fijian has faced in the ring outside of his home country and the first non-Fijian.

Rapira is rapt to be a part of a David Tua fight night.

"I'm stoked that I'm going to be there to see the fight. It's a dream come true for me because David has been a huge hero of mine. He's always been one of my favourite boxers, so to fight on his card is such an honour."